RESUMO
To determine the preventive effect of postmenopausal hormone replacement therapy on cerebrovascular disease. A randomized prospective study included 46 postmenopausal non hystrectomized women, designed to evaluate the changes produced by oral combined sequential hormone therapy in body mass index, blood pressure, total cholesterol, triglycerides high density lipoprotein cholesterol, low density lipoprotein cholesterol, internal carotid artery pulsatility index and two cognitive function tests. Women were randomly allocated into 2 groups; the 1st received oral oestradiol valerate 2 mg and norgestrel 0.5mg "cyclo-progynova" and the 2nd who refused hormone therapy, as a control group. Women who received hormone therapy showed significant drop in their total cholesterol, low density lipoprotein cholesterol and internal carotid artery pulsatility index associated with significant increase of high density lipoprotein cholesterol and maintained cognitive functions. Those in the 2nd group showed significant increase in their total cholesterol, low density lipoprotein cholesterol and internal carotid artery pulsatility index associated with deterioration in cognitive functions. No significant change in other parameters. Postmenopausal oral combined sequential hormone therapy decreases, internal carotid artery pulsatility index, reflecting low cerebral vascular resistance This may be the mechanism by which postmenopausal hormone replacement therapy maintains cerebral functions